CLINICAL SPOTLIGHT
Heart, Lung and Circulation (2014) 23, e248–e250 1443-9506/04/$36.00 http://dx.doi.org/10.1016/j.hlc.2014.07.061
Cardiac Vignette: Isolated Pulmonary Regurgitation Chieh Howe (Gary) Gan, MBBS *, Aditya Bhat, MBBS, Suzanne Eshoo, MBBS PhD FRACP FCSANZ, A. Robert Denniss, MD MSc FRACP FCSANZ FESC FACC Department of Cardiology, Blacktown Hospital, and University of Western Sydney, Sydney, NSW, Australia Received 21 January 2014; received in revised form 12 June 2014; accepted 11 July 2014; online published-ahead-of-print 24 July 2014
Isolated pulmonary regurgitation (PR) is a rare occurrence with only a handful of documented cases worldwide. Though usually well tolerated in childhood, chronic PR can eventually lead to RV dysfunction and ventricular arrhythmias. In this cardiac vignette, we describe a case of isolated PR in a young female presenting with syncope and explore the natural history, different investigative modalities as well as issues in clinical management of this rare condition. Keywords
Isolated pulmonary regurgitation Pulmonary regurgitation Valvular heart disease Congenital heart disease Flail pulmonary valve
Introduction Functional or acquired pulmonary regurgitation (PR) is a relatively common occurrence and can result from any condition that causes dilatation of the pulmonary artery or valve annulus. Congenital organic PR, on the other hand, is considerably rare, even more so when it occurs in isolation. There have been a handful of documented cases of isolated PR in the literature. Though usually well tolerated in childhood due to adaptive right ventricular (RV) response to fluid overload and low pressure pulmonary microvasculature, chronic PR can lead to progressive RV dilatation and with time, RV dysfunction, exercise intolerance, ventricular arrhythmias and sudden cardiac death. [1] In this cardiac vignette, we report the first documented case of isolated PR in Australia. We explore the issues associated with diagnosis, echocardiographic and magnetic resonance assessment, as well as clinical management of this rare condition.
Case History A 21 year-old Liberian female with no previous medical history presented with an unwitnessed syncopal episode.
The duration of the syncope was unclear and occurred in the context of an episode of epistaxis that spontaneously resolved on presentation to the Emergency Department. There were no reports of chest pain, palpitations or shortness of breath preceding the event. There were also no reports of tongue biting or urinary incontinence. The patient recovered from the syncopal event spontaneously at which point some non-specific chest and upper back pain was reported. She denied any recent illnesses but described an 18-month history of progressive exertional dyspnoea and chest discomfort that followed the birth of her first and only child. The patient arrived in Australia at the age of 13 as a refugee with her siblings (including her twin sister) and her stepmother. She was separated from her partner and worked in Disability Community Services to support herself and her son. She is a non-smoker, enjoyed alcohol socially and denied any recreational drug use. She did not have any problems with her pregnancy and had a normal vaginal delivery. On examination, the patient appeared well and had a normal body habitus (BMI 23.7). Blood pressure was 118/ 74 mmHg without orthostatic changes. Heart rate was regular at 80 bpm with symmetrical radial pulses. Cardiovascular assessment revealed a Grade 3 diastolic murmur that was loudest over the pulmonary area. There were no clinical
*Corresponding author at:. Email: [email protected] Crown Copyright © 2014 Published by Elsevier Inc on behalf of Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). All rights reserved.
e249
Isolated Pulmonary Regurgitation
features of pulmonary hypertension or congestive cardiac failure. Respiratory assessment was unremarkable and neurological assessment revealed no focal neurological deficits. Routine blood tests were unremarkable. The electrocardiogram showed normal sinus rhythm. Chest X-ray showed
Figure 1 Right Ventricular Dilatation.
Figure 2 Flail Pulmonary Valve with Severe Pulmonary Regurgitation.
Figure 3 Cardiac MRI.
clear lung fields with mild cardiomegaly. A transthoracic echocardiogram (Figures 1 and Figure 2) was performed which revealed a flail pulmonary valve with severe pulmonary regurgitation and moderate right ventricular dilatation. CT pulmonary angiogram excluded pulmonary embolus. Cardiac magnetic resonance (Figures 3) was subsequently performed which revealed mild-to-moderate right ventricular dilatation (RV EDV 1.94x the LV EDV) with a low normal RV systolic function (EF 54%, TAPSE 20 mm) and a mildly dilated and expansile RVOT. There was severe PR with a regurgitant fraction of 41%. No regional wall motion abnormalities or delayed gadolinium enhancement in the RV was noted nor were there any other structural or valvular abnormalities. The patient is currently being followed in the community by a cardiac congenital specialist, with the aim of eventual surgical intervention.
Discussion Pulmonary regurgitation generally has a long asymptomatic lag-time due to chronic RV adaptation. This is facilitated by the indirect maintenance of forward pulmonary flow by the left heart and low-resistance pulmonary microcirculation both of which prevent acute RV deterioration even in the presence of pulmonary valvular insufficiency. [1,2] With progressive regurgitation, however, increase in end diastolic volume ensues followed by an increase in end systolic volume, dilatation of the RV cavity and eventually, RV dysfunction. Clinical symptoms can vary from different degrees of exercise intolerance to symptoms of congestive cardiac failure. Exertional dyspnoea is common and of multifactorial aetiology in this disease. Reduced aerobic capacity is mediated via reduced preload to the left ventricle and thus, inadequate systemic blood flow to active skeletal musculature during exercise. [3,4] Mechanoreceptors located in RV and right atrium further contribute to the sensation of dyspnoea via elevated pressure-related myocardial stretch, leading to enhanced afferent sympathetic activity towards key centres in the brainstem which regulate ventilation and the sensation of breathing. [4] Additionally, a predisposition to development of atrial and ventricular tachyarrhythmias may result from slowing of intraventricular conduction (a predisposing substrate for the development of re-entrant circuits) due to stretching of the right ventricle. At onset of symptoms, RV dysfunction is usually well established. [2] Although the presenting complaint in this case was of syncope, this was felt to be vasovagal in nature and unrelated to the patient’s underlying cardiac disease. Echocardiography is first line with regards to diagnosis and investigation of PR. Two-dimensional echocardiography enables evaluation of pulmonary valve morphology as well as RV parameters. Doppler techniques are useful for visualisation of regurgitant flow and to establish the presence of pulmonary arterial hypertension. Severity of PR can be ascertained via colour flow Doppler. [2] Though limited by costs
e250
and availability in clinical practice, Cardiac Magnetic Resonance (CMR) provides excellent temporal and spatial definition of cardiac structures and allows accurate assessment of pulmonary valve and RV structures, as well as accurate estimates of severity of regurgitation, mechanism of regurgitation and right ventricular function. These geometric dimensions are essential in the pre-operative workup for surgical intervention. [3] Other ancillary investigations include plain radiographs which can reveal RV enlargement and dilatation of the pulmonary trunk as well as the electrocardiogram (ECG) to assess for RV hypertrophy or strain, and exclude malignant arrhythmias. [2] Primary medical management is mediated mainly through diuretic therapy, which is utilised mainly for acute cardiac decompensation. Though prognostically beneficial in left ventricular dysfunction and coronary artery disease, neurohumoral antagonism is of less certain benefit in PR but should still be considered and may improve symptoms. [2] Surgical treatment of PR, namely via pulmonary valve replacement (PVR) prevents further RV dysfunction and has been shown to improve New York Heart Association Functional Class status, quality of life, and reduce risk for development of RV tachyarrhythmias and sudden cardiac death. Though robust data is lacking with regards to surgical management of isolated PR, utilisation of PVR in patients with complex congenital cardiac disease involving the pulmonary valve (e.g. Tetralogy of Fallot, congenital PV stenosis) has shown promising survival benefits. [5] PVR is generally indicated in patients with moderate-to-severe (EROA >21-115 mm2 and regurgitation volume >15-115 mL) or severe PR (EROA >21 mm2 and regurgitation volume >115 mL) with progressive RV dilatation and dysfunction, irrespective of presence of overt symptoms. [6] The optimal timing of PVR remains controversial and is crucial to preservation of RV function and overall clinical outcome. Performed late, RV recovery is variable and symptoms of RV dysfunction may persist. Patients with established RV dysfunction are also subject to higher peri-operative risk. [7] Prosthesis profiles differ with tissue characteristics, bioprosthetic valves having lower thromboembolic complications at the cost of shorter half-lives in comparison to mechanical prosthesis. [8] In cases of severe distortion of RV outflow tract, pulmonary infundibuloplasty can also be considered and has been shown to improve volumes and geometry thereby improving RV performance. [9] In cases of documented ventricular tachyarrhythmias or cardiac arrest, automatic implantable defibrillators may be warranted as prophylactic therapy. [10] New modalities are emerging with regards to interventional management of PR. One of these is the transcatheter implantation of the pulmonary valve. This intervention is less invasive relative to PVR, avoids the need for cardiopulmonary bypass and reduces risk of peri-operative bleeding and infection. The primary limitation is the constraint of optimal pre-operative valvular dimension for valve implantation. In patients with right ventricular outflow tract dilatation, common in chronic PR, RV geometry is unfavourable
C.H.G. Gan et al.
for transcatheter valve positioning and fit. Preliminary data has shown a high rate of procedural success and promising short-term valvular function post-transcatheter implantation, with low rates of stent fracture, misalignment and freedom from re-intervention in patients with suitable anatomy. Further studies are required to evaluate longer term results. [11,12]
Conclusion Isolated PR is a rare cardiac condition, which requires careful evaluation and assessment. Primary diagnosis is warranted through echocardiography, with CMR used for better delineation of cardiac anatomy and function as part of the preoperative workup. Surgical management is the gold standard for prevention of RV dysfunction, with medical management playing a primary role in acute cardiac decompensation and symptomatic management. Transcatheter approaches for valve implantation are relatively new and may offer expanded roles in the future.
References [1] Harrild DM, Powell AJ, Trang TX, Geva T, Lock JE, Rhodes J, et al. Longterm pulmonary regurgitation following balloon valvuloplasty for pulmonary stenosis risk factors and relationship to exercise capacity and ventricular volume and function. J Am Coll Cardiol 2010;55(Mar 9 (10)):1041–7. [2] Bruce CJ, Connolly HM. Right-sided valve disease deserves a little more respect. Circulation 2009;119(May 26 (20)):2726–34. [3] Pin˜a IL, Apstein CS, Balady GJ, Belardinelli R, Chaitman BR, Duscha BD, et al. Exercise and heart failure: A statement from the American Heart Association Committee on exercise, rehabilitation, and prevention. Circulation 2003;107(Mar 4 (8)):1210–25. [4] Fowler RM, Gain KR, Gabbay E. Exercise intolerance in pulmonary arterial hypertension. Pulm Med 2012;2012(Jun 10):359204. [5] Sorrell VL, Altbach MI, Kudithipudi V, Squire SW, Goldberg SJ, Klewer SE, et al. is an important complementary tool to Doppler echocardiography in the management of patients with pulmonary regurgitation. Echocardiography 2007;24(Mar (3)):316–28. [6] Ferraz Cavalcanti PE, Sa´ MP, Santos CA, Esmeraldo IM, Escobar RR, Menezes AM, et al. Pulmonary valve replacement after operative repair of tetralogy of fallot: meta-analysis and meta-regression of 3,118 patients from 48 studies. J Am Coll Cardiol 2013;62(Dec 10 (23)): 2227–43. [7] Lancellotti P, Tribouilloy C, Hagendorff A, Moura L, Popescu BA, Agricola E, et al. European Association of Echocardiography recommendations for the assessment of valvular regurgitation. Part 1: aortic and pulmonary regurgitation (native valve disease). Eur J Echocardiogr 2010;11(Apr (3)):223–44. [8] Davlouros PA, Karatza AA, Gatzoulis MA, Shore DF. Timing and type of surgery for severe pulmonary regurgitation after repair of tetralogy of Fallot. Int J Cardiol 2004;97(Dec Suppl 1):91–101. [9] Waterbolk T, Hoendermis E, den Hamer I, Ebels T. Pulmonary valve replacement with a mechanical prosthesis: promising results of 28 procedures in patients with congenital heart disease. Eur J Cardiothorac Surg 2006;30:28–32. [10] d’Udekem d’Acoz Y, Pasquet A, Van Caenegem O, Barrea C, Sluysmans T, Noirhomme P, et al. Reoperation for severe right ventricular dilatation after tetralogy of Fallot repair: pulmonary infundibuloplasty should be added to homograft implantation. J Heart Valve Dis 2004;13(Mar (2)): 307–12. [11] Le Gloan L, Khairy P. Management of arrhythmias in patients with tetralogy of Fallot. Curr Opin Cardiol 2011;26(Jan (1)):60–5. [12] McElhinney DB, Hellenbrand WE, Zahn EM, Jones TK, Cheatham JP, Lock JE, et al. Short- and Medium-Term Outcomes After Transcatheter Pulmonary Valve Placement in the Expanded Multicenter US Melody Valve Trial. Circulation 2010;122(Aug 3 (5)):507–16.
Heart, Lung and Circulation (2014) 23, e248–e250 1443-9506/04/$36.00 http://dx.doi.org/10.1016/j.hlc.2014.07.061
Cardiac Vignette: Isolated Pulmonary Regurgitation Chieh Howe (Gary) Gan, MBBS *, Aditya Bhat, MBBS, Suzanne Eshoo, MBBS PhD FRACP FCSANZ, A. Robert Denniss, MD MSc FRACP FCSANZ FESC FACC Department of Cardiology, Blacktown Hospital, and University of Western Sydney, Sydney, NSW, Australia Received 21 January 2014; received in revised form 12 June 2014; accepted 11 July 2014; online published-ahead-of-print 24 July 2014
Isolated pulmonary regurgitation (PR) is a rare occurrence with only a handful of documented cases worldwide. Though usually well tolerated in childhood, chronic PR can eventually lead to RV dysfunction and ventricular arrhythmias. In this cardiac vignette, we describe a case of isolated PR in a young female presenting with syncope and explore the natural history, different investigative modalities as well as issues in clinical management of this rare condition. Keywords
Isolated pulmonary regurgitation Pulmonary regurgitation Valvular heart disease Congenital heart disease Flail pulmonary valve
Introduction Functional or acquired pulmonary regurgitation (PR) is a relatively common occurrence and can result from any condition that causes dilatation of the pulmonary artery or valve annulus. Congenital organic PR, on the other hand, is considerably rare, even more so when it occurs in isolation. There have been a handful of documented cases of isolated PR in the literature. Though usually well tolerated in childhood due to adaptive right ventricular (RV) response to fluid overload and low pressure pulmonary microvasculature, chronic PR can lead to progressive RV dilatation and with time, RV dysfunction, exercise intolerance, ventricular arrhythmias and sudden cardiac death. [1] In this cardiac vignette, we report the first documented case of isolated PR in Australia. We explore the issues associated with diagnosis, echocardiographic and magnetic resonance assessment, as well as clinical management of this rare condition.
Case History A 21 year-old Liberian female with no previous medical history presented with an unwitnessed syncopal episode.
The duration of the syncope was unclear and occurred in the context of an episode of epistaxis that spontaneously resolved on presentation to the Emergency Department. There were no reports of chest pain, palpitations or shortness of breath preceding the event. There were also no reports of tongue biting or urinary incontinence. The patient recovered from the syncopal event spontaneously at which point some non-specific chest and upper back pain was reported. She denied any recent illnesses but described an 18-month history of progressive exertional dyspnoea and chest discomfort that followed the birth of her first and only child. The patient arrived in Australia at the age of 13 as a refugee with her siblings (including her twin sister) and her stepmother. She was separated from her partner and worked in Disability Community Services to support herself and her son. She is a non-smoker, enjoyed alcohol socially and denied any recreational drug use. She did not have any problems with her pregnancy and had a normal vaginal delivery. On examination, the patient appeared well and had a normal body habitus (BMI 23.7). Blood pressure was 118/ 74 mmHg without orthostatic changes. Heart rate was regular at 80 bpm with symmetrical radial pulses. Cardiovascular assessment revealed a Grade 3 diastolic murmur that was loudest over the pulmonary area. There were no clinical
*Corresponding author at:. Email: [email protected] Crown Copyright © 2014 Published by Elsevier Inc on behalf of Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). All rights reserved.
e249
Isolated Pulmonary Regurgitation
features of pulmonary hypertension or congestive cardiac failure. Respiratory assessment was unremarkable and neurological assessment revealed no focal neurological deficits. Routine blood tests were unremarkable. The electrocardiogram showed normal sinus rhythm. Chest X-ray showed
Figure 1 Right Ventricular Dilatation.
Figure 2 Flail Pulmonary Valve with Severe Pulmonary Regurgitation.
Figure 3 Cardiac MRI.
clear lung fields with mild cardiomegaly. A transthoracic echocardiogram (Figures 1 and Figure 2) was performed which revealed a flail pulmonary valve with severe pulmonary regurgitation and moderate right ventricular dilatation. CT pulmonary angiogram excluded pulmonary embolus. Cardiac magnetic resonance (Figures 3) was subsequently performed which revealed mild-to-moderate right ventricular dilatation (RV EDV 1.94x the LV EDV) with a low normal RV systolic function (EF 54%, TAPSE 20 mm) and a mildly dilated and expansile RVOT. There was severe PR with a regurgitant fraction of 41%. No regional wall motion abnormalities or delayed gadolinium enhancement in the RV was noted nor were there any other structural or valvular abnormalities. The patient is currently being followed in the community by a cardiac congenital specialist, with the aim of eventual surgical intervention.
Discussion Pulmonary regurgitation generally has a long asymptomatic lag-time due to chronic RV adaptation. This is facilitated by the indirect maintenance of forward pulmonary flow by the left heart and low-resistance pulmonary microcirculation both of which prevent acute RV deterioration even in the presence of pulmonary valvular insufficiency. [1,2] With progressive regurgitation, however, increase in end diastolic volume ensues followed by an increase in end systolic volume, dilatation of the RV cavity and eventually, RV dysfunction. Clinical symptoms can vary from different degrees of exercise intolerance to symptoms of congestive cardiac failure. Exertional dyspnoea is common and of multifactorial aetiology in this disease. Reduced aerobic capacity is mediated via reduced preload to the left ventricle and thus, inadequate systemic blood flow to active skeletal musculature during exercise. [3,4] Mechanoreceptors located in RV and right atrium further contribute to the sensation of dyspnoea via elevated pressure-related myocardial stretch, leading to enhanced afferent sympathetic activity towards key centres in the brainstem which regulate ventilation and the sensation of breathing. [4] Additionally, a predisposition to development of atrial and ventricular tachyarrhythmias may result from slowing of intraventricular conduction (a predisposing substrate for the development of re-entrant circuits) due to stretching of the right ventricle. At onset of symptoms, RV dysfunction is usually well established. [2] Although the presenting complaint in this case was of syncope, this was felt to be vasovagal in nature and unrelated to the patient’s underlying cardiac disease. Echocardiography is first line with regards to diagnosis and investigation of PR. Two-dimensional echocardiography enables evaluation of pulmonary valve morphology as well as RV parameters. Doppler techniques are useful for visualisation of regurgitant flow and to establish the presence of pulmonary arterial hypertension. Severity of PR can be ascertained via colour flow Doppler. [2] Though limited by costs
e250
and availability in clinical practice, Cardiac Magnetic Resonance (CMR) provides excellent temporal and spatial definition of cardiac structures and allows accurate assessment of pulmonary valve and RV structures, as well as accurate estimates of severity of regurgitation, mechanism of regurgitation and right ventricular function. These geometric dimensions are essential in the pre-operative workup for surgical intervention. [3] Other ancillary investigations include plain radiographs which can reveal RV enlargement and dilatation of the pulmonary trunk as well as the electrocardiogram (ECG) to assess for RV hypertrophy or strain, and exclude malignant arrhythmias. [2] Primary medical management is mediated mainly through diuretic therapy, which is utilised mainly for acute cardiac decompensation. Though prognostically beneficial in left ventricular dysfunction and coronary artery disease, neurohumoral antagonism is of less certain benefit in PR but should still be considered and may improve symptoms. [2] Surgical treatment of PR, namely via pulmonary valve replacement (PVR) prevents further RV dysfunction and has been shown to improve New York Heart Association Functional Class status, quality of life, and reduce risk for development of RV tachyarrhythmias and sudden cardiac death. Though robust data is lacking with regards to surgical management of isolated PR, utilisation of PVR in patients with complex congenital cardiac disease involving the pulmonary valve (e.g. Tetralogy of Fallot, congenital PV stenosis) has shown promising survival benefits. [5] PVR is generally indicated in patients with moderate-to-severe (EROA >21-115 mm2 and regurgitation volume >15-115 mL) or severe PR (EROA >21 mm2 and regurgitation volume >115 mL) with progressive RV dilatation and dysfunction, irrespective of presence of overt symptoms. [6] The optimal timing of PVR remains controversial and is crucial to preservation of RV function and overall clinical outcome. Performed late, RV recovery is variable and symptoms of RV dysfunction may persist. Patients with established RV dysfunction are also subject to higher peri-operative risk. [7] Prosthesis profiles differ with tissue characteristics, bioprosthetic valves having lower thromboembolic complications at the cost of shorter half-lives in comparison to mechanical prosthesis. [8] In cases of severe distortion of RV outflow tract, pulmonary infundibuloplasty can also be considered and has been shown to improve volumes and geometry thereby improving RV performance. [9] In cases of documented ventricular tachyarrhythmias or cardiac arrest, automatic implantable defibrillators may be warranted as prophylactic therapy. [10] New modalities are emerging with regards to interventional management of PR. One of these is the transcatheter implantation of the pulmonary valve. This intervention is less invasive relative to PVR, avoids the need for cardiopulmonary bypass and reduces risk of peri-operative bleeding and infection. The primary limitation is the constraint of optimal pre-operative valvular dimension for valve implantation. In patients with right ventricular outflow tract dilatation, common in chronic PR, RV geometry is unfavourable
C.H.G. Gan et al.
for transcatheter valve positioning and fit. Preliminary data has shown a high rate of procedural success and promising short-term valvular function post-transcatheter implantation, with low rates of stent fracture, misalignment and freedom from re-intervention in patients with suitable anatomy. Further studies are required to evaluate longer term results. [11,12]
Conclusion Isolated PR is a rare cardiac condition, which requires careful evaluation and assessment. Primary diagnosis is warranted through echocardiography, with CMR used for better delineation of cardiac anatomy and function as part of the preoperative workup. Surgical management is the gold standard for prevention of RV dysfunction, with medical management playing a primary role in acute cardiac decompensation and symptomatic management. Transcatheter approaches for valve implantation are relatively new and may offer expanded roles in the future.
References [1] Harrild DM, Powell AJ, Trang TX, Geva T, Lock JE, Rhodes J, et al. Longterm pulmonary regurgitation following balloon valvuloplasty for pulmonary stenosis risk factors and relationship to exercise capacity and ventricular volume and function. J Am Coll Cardiol 2010;55(Mar 9 (10)):1041–7. [2] Bruce CJ, Connolly HM. Right-sided valve disease deserves a little more respect. Circulation 2009;119(May 26 (20)):2726–34. [3] Pin˜a IL, Apstein CS, Balady GJ, Belardinelli R, Chaitman BR, Duscha BD, et al. Exercise and heart failure: A statement from the American Heart Association Committee on exercise, rehabilitation, and prevention. Circulation 2003;107(Mar 4 (8)):1210–25. [4] Fowler RM, Gain KR, Gabbay E. Exercise intolerance in pulmonary arterial hypertension. Pulm Med 2012;2012(Jun 10):359204. [5] Sorrell VL, Altbach MI, Kudithipudi V, Squire SW, Goldberg SJ, Klewer SE, et al. is an important complementary tool to Doppler echocardiography in the management of patients with pulmonary regurgitation. Echocardiography 2007;24(Mar (3)):316–28. [6] Ferraz Cavalcanti PE, Sa´ MP, Santos CA, Esmeraldo IM, Escobar RR, Menezes AM, et al. Pulmonary valve replacement after operative repair of tetralogy of fallot: meta-analysis and meta-regression of 3,118 patients from 48 studies. J Am Coll Cardiol 2013;62(Dec 10 (23)): 2227–43. [7] Lancellotti P, Tribouilloy C, Hagendorff A, Moura L, Popescu BA, Agricola E, et al. European Association of Echocardiography recommendations for the assessment of valvular regurgitation. Part 1: aortic and pulmonary regurgitation (native valve disease). Eur J Echocardiogr 2010;11(Apr (3)):223–44. [8] Davlouros PA, Karatza AA, Gatzoulis MA, Shore DF. Timing and type of surgery for severe pulmonary regurgitation after repair of tetralogy of Fallot. Int J Cardiol 2004;97(Dec Suppl 1):91–101. [9] Waterbolk T, Hoendermis E, den Hamer I, Ebels T. Pulmonary valve replacement with a mechanical prosthesis: promising results of 28 procedures in patients with congenital heart disease. Eur J Cardiothorac Surg 2006;30:28–32. [10] d’Udekem d’Acoz Y, Pasquet A, Van Caenegem O, Barrea C, Sluysmans T, Noirhomme P, et al. Reoperation for severe right ventricular dilatation after tetralogy of Fallot repair: pulmonary infundibuloplasty should be added to homograft implantation. J Heart Valve Dis 2004;13(Mar (2)): 307–12. [11] Le Gloan L, Khairy P. Management of arrhythmias in patients with tetralogy of Fallot. Curr Opin Cardiol 2011;26(Jan (1)):60–5. [12] McElhinney DB, Hellenbrand WE, Zahn EM, Jones TK, Cheatham JP, Lock JE, et al. Short- and Medium-Term Outcomes After Transcatheter Pulmonary Valve Placement in the Expanded Multicenter US Melody Valve Trial. Circulation 2010;122(Aug 3 (5)):507–16.
